-2x^2-15x+7=0

Solution for -2x^2-15x+7=0 equation:

-2x^2-15x+7=0

a = -2; b = -15; c = +7;
Δ = b2-4ac
Δ = -152-4·(-2)·7
Δ = 281
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-\sqrt{281}}{2*-2}=\frac{15-\sqrt{281}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+\sqrt{281}}{2*-2}=\frac{15+\sqrt{281}}{-4}
$